I also loved, 'The Dark Half' though less on re-reading than first time.
The Dark Tower is really, really not Sci Fi -honest!
I don't read any other 'horror' writers because I haven't found any good ones. I liked one of Dean K's but thought the others of his I read were dreadful. He is really samey and nowhere near as good on characterisation or even on pure CARE-appeal than King is - and he's got what I read as a major Christian-streak going on in his books which irritates me.